1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. 3 4 #include <linux/console.h> 5 #include <linux/memblock.h> 6 #include <linux/initrd.h> 7 #include <linux/of.h> 8 #include <linux/of_fdt.h> 9 #include <linux/start_kernel.h> 10 #include <linux/dma-map-ops.h> 11 #include <asm/sections.h> 12 #include <asm/mmu_context.h> 13 #include <asm/pgalloc.h> 14 15 #ifdef CONFIG_BLK_DEV_INITRD 16 static void __init setup_initrd(void) 17 { 18 unsigned long size; 19 20 if (initrd_start >= initrd_end) { 21 pr_err("initrd not found or empty"); 22 goto disable; 23 } 24 25 if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) { 26 pr_err("initrd extends beyond end of memory"); 27 goto disable; 28 } 29 30 size = initrd_end - initrd_start; 31 32 if (memblock_is_region_reserved(__pa(initrd_start), size)) { 33 pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region", 34 __pa(initrd_start), size); 35 goto disable; 36 } 37 38 memblock_reserve(__pa(initrd_start), size); 39 40 pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n", 41 (void *)(initrd_start), size); 42 43 initrd_below_start_ok = 1; 44 45 return; 46 47 disable: 48 initrd_start = initrd_end = 0; 49 50 pr_err(" - disabling initrd\n"); 51 } 52 #endif 53 54 void __init arch_zone_limits_init(unsigned long *max_zone_pfns) 55 { 56 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 57 #ifdef CONFIG_HIGHMEM 58 max_zone_pfns[ZONE_HIGHMEM] = max_pfn; 59 #endif 60 } 61 62 static void __init csky_memblock_init(void) 63 { 64 unsigned long lowmem_size = PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET); 65 unsigned long sseg_size = PFN_DOWN(SSEG_SIZE - PHYS_OFFSET_OFFSET); 66 signed long size; 67 68 memblock_reserve(__pa(_start), _end - _start); 69 70 early_init_fdt_reserve_self(); 71 early_init_fdt_scan_reserved_mem(); 72 73 memblock_dump_all(); 74 75 min_low_pfn = PFN_UP(memblock_start_of_DRAM()); 76 max_low_pfn = max_pfn = PFN_DOWN(memblock_end_of_DRAM()); 77 78 size = max_pfn - min_low_pfn; 79 80 if (size >= lowmem_size) { 81 max_low_pfn = min_low_pfn + lowmem_size; 82 #ifdef CONFIG_PAGE_OFFSET_80000000 83 write_mmu_msa1(read_mmu_msa0() + SSEG_SIZE); 84 #endif 85 } else if (size > sseg_size) { 86 max_low_pfn = min_low_pfn + sseg_size; 87 } 88 89 #ifdef CONFIG_BLK_DEV_INITRD 90 setup_initrd(); 91 #endif 92 93 mmu_init(min_low_pfn, max_low_pfn); 94 95 #ifdef CONFIG_HIGHMEM 96 97 highstart_pfn = max_low_pfn; 98 highend_pfn = max_pfn; 99 #endif 100 memblock_set_current_limit(PFN_PHYS(max_low_pfn)); 101 102 dma_contiguous_reserve(0); 103 } 104 105 void __init setup_arch(char **cmdline_p) 106 { 107 *cmdline_p = boot_command_line; 108 109 console_verbose(); 110 111 pr_info("Phys. mem: %ldMB\n", 112 (unsigned long) memblock_phys_mem_size()/1024/1024); 113 114 setup_initial_init_mm(_start, _etext, _edata, _end); 115 116 parse_early_param(); 117 118 csky_memblock_init(); 119 120 unflatten_and_copy_device_tree(); 121 122 #ifdef CONFIG_SMP 123 setup_smp(); 124 #endif 125 126 fixaddr_init(); 127 128 #ifdef CONFIG_HIGHMEM 129 kmap_init(); 130 #endif 131 } 132 133 unsigned long va_pa_offset; 134 EXPORT_SYMBOL(va_pa_offset); 135 136 static inline unsigned long read_mmu_msa(void) 137 { 138 #ifdef CONFIG_PAGE_OFFSET_80000000 139 return read_mmu_msa0(); 140 #endif 141 142 #ifdef CONFIG_PAGE_OFFSET_A0000000 143 return read_mmu_msa1(); 144 #endif 145 } 146 147 asmlinkage __visible void __init csky_start(unsigned int unused, 148 void *dtb_start) 149 { 150 /* Clean up bss section */ 151 memset(__bss_start, 0, __bss_stop - __bss_start); 152 153 va_pa_offset = read_mmu_msa() & ~(SSEG_SIZE - 1); 154 155 pre_trap_init(); 156 157 if (dtb_start == NULL) 158 early_init_dt_scan(__dtb_start, __pa(dtb_start)); 159 else 160 early_init_dt_scan(dtb_start, __pa(dtb_start)); 161 162 start_kernel(); 163 164 asm volatile("br .\n"); 165 } 166